<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Css clip</title>
	<style>
	.icos {
		width: 800px;
		height: 600px;
		background: url(ico.gif) no-repeat;
		position: absolute; /*clip 要与absolute或fixed一起才起作用*/
		overflow: hidden;
	}
	.icos:hover {
		clip: rect(150px 135px 240px 25px); /* IE 8-*/
		clip: rect(150px, 135px, 240px, 25px);
	}
	</style>
</head>
<body>
	<div class="icos"></div>
</body>
</html>